Draft-regulator



`(No Model.)

yJ. Q.`BVERSON. DRAFT REGULATOR.

'Patented sept. 8, 1885.

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- J UNITED STATES PATENT OFFICE.,

JOHN Q. EvERsoN, oF rrrrsBUaG, PnNNsYLvANrA DRAFT-REGULATO R.

SPECIFICATION forming part of Letters Patent No. 325,791, dated September 8, 1885.

Application filed May 25, 1855. (No model.)

To all whom it may concerm. i

Be it known that I, JOHN Q. EvERsoN, a

citizen of the United States, residing at Pittsburg, in the county of Allegheny and State of Pennsylvania', havel invented a new andV useful Improvement in Draft-Regulators; and I hereby declare the following to be a full, clear, and exact description thereof', reference being had to the accompanying drawings, in which- Figure l represents a longitudinal section ofa iiued steam-boiler and stack with the safety-valve and blow-off pipe attached. Fi g. 2 is a front elevation of same.

Like letters of reference indicate like parts wherever they occur.

In ordinary mill, factory, and tow-boat practice there are many sudden and interrupted demands for varying degrees of engine-power, consequently the demand for steam is unequal and interrupted to a greater or less degree in all instances. It is usual, therefore, inall plants designed forsuch purposes to provide boilers adapted to develop a little more than the medium amount of steam required, and to meet extra demands by more or less hard ring. These circumstances often lead to the rapid development of steam and the quick raising of pressure to and above the safety or blow-off limit. At the latter point the steam-escape valve opens and the steam blows oft' until the pressure falls down to the safety limit.

In-every well-regulated factory, boat, or mill it is usual to throw open the furnacedoor and flue-'caps during the time the steam is blowing off through the safety-valve. This is done for the purpose of stopping the draft and thereby retarding the generation of steam at such periods. In cases where there is en gine stoppage and a very hot fire is under the boilers the escape-valve may be of insufficient size to carry off the surplus steam as rapidly as the demands of safety call for; hence it is not only advisable, but imperatively necessary in many instances, that the caps of the iiues and the doors should be opened to stop the draft, or that some other means should be provided for retarding steam-generation. In the use of my invention I propose, therefore, to cure such defects, and to also produce other new and advantageous effects by utilizing the waste steam from thel blow-off valve for the purpose of retarding the draft, regulatingthe pressure, and cleaning the flues.

In the construction of my apparatus as applied to a battery of two double-fined steamboilers I attach a pipe, A, to the safety-valve B. The other end of the pipe A enters the stack C, and the branches enter the iiues of` the boiler. The pipe A should be as large as the opening in the safety-valve` and the aggregate of the branches should be somewhat greater, so that the escape of the steam from the safety-valve will not be retarded in any manner.

In the practice of my invention, when from any cause the steam exceeds the safety limit, it raises the safety-valve B, and escapes through the pipe A into the flues H I J K, and not only reverses the draft, but forces the gases that are nonsupporters of combustion back on and into the fires, which tends to cool the fire, lower the temperature, and reduce the pressure below the safety limit. The safety-valve then closes, the fire again burns, and the hot gases are drawn through the iiues int-o the stack;and so, whenever the safetyvalve blows 0E, the fire is cooled down and kept from burning until the safety-valve is again closed.

By the use of my invention an automatic regulation of steampressure is secured by utilizing the waste steam escaping from the safety-valve to reverse the draft and cool the tires. Another very important effect is secured. It is well known that soot and ashes settle in the flues and retard the generation of steam, as such deposits are non-conductors of heat. Now by the use of my invention the escaping steam blows out all the soot and ashes, and keeps the lues constantly clean, so that it is not only a steam-regulating but also a steam-generating improvement.

The advantages of my inventionare: it reverses the draft and checks the generation of steam when above the safety limit; it obviates the necessity of opening the doors and 'letting in cold air, which is so destructive to IOO it saves [nel by retarding the draft when the steam is too high. The noise of escaping steam from the safety-valve is prevented, as it escapes into the flues and is not heard.

The lues may also be cleaned at any time by raising the safety-valve by hand, if it is desired. The improvement `may also be applied t0 tubular or to plain cylinder boilers. In the latter case the steam should escape in the opposite direction to the draft, so that the draft and gases resulting from combustion shall bc checked or reversed.

What I claim, and desire to secure by Let- The combination, with a steam-boiler hav- 15 ing a safety-valve and fire-fines on the inside7 of a tube connecting at one end with the opening closed by said valve, and at the other provided with branch pipes, each of which enters a iire-flue in the boiler, as and for the 2o Witnesses:

S. M. REYNOLDS, JOHN JORDAN. 

